So you’ve got a problem and you decide to fire up Wireshark and take a capture. When you look at the packets you see a bunch of them that are far larger than the 1500 byte MTU. HOW CAN THIS BE?!?!? There’s something you need to know about taking captures on the host that is […]
By Kary | case study
So far I’ve mostly shown you concepts and techniques to analyze performance. Well, now I’m gonna solve a real world problem with packet analysis and walk you through it how I did it. Brandon joined the PacketBomb email list and we were email chatting about packet analysis. He mentioned a problem he was trying to […]
Make sure you’ve read Understanding Throughput and TCP Windows before watching this video. I mean, you don’t HAVE to, but I recommend it. No one’s ever asked you why the network is slow, right? Hahahahahaaaaaaa haa ha. Ha. Oh man. What a funny joke. The better question is can you think of a day in which […]
Throughput is generally measured in the amount of data sent over time e.g. bits or bytes per second. Sending more bits in a shorter amount of time equals higher throughput. So let’s talk about some of the factors that control how much data can be sent in a given time period. Here’s some data represented […]
(I’ll explain this picture later.) This whole thing started when I posted Why don’t more people know how to do packet analysis? on reddit. Up to that point, I thought maybe it was just me and a few others who valued and dug packet analysis since I hadn’t met many people who could do it […]
Or prove that it is the network. If you’re a network engineer, how much time do you spend defending the network? Everyone points a finger at the network; it’s guilty until proven innocent. Everything looks good from your standpoint: monitoring, alerts, maybe some pings, download a file from a server…it all seems to check out. […]
If I’m troubleshooting a performance issue, one of the first tools I reach for in Wireshark is under Statistics > TCP StreamGraph > Time-Sequence Graph (tcptrace). At a glance I can tell if this is going to be an easy one to analyze or if I’m gonna have to roll up my sleeves and dive […]
In this video you will learn: How to connect to a server protected by a Cisco router ACL How to manipulate TCP flags of packets sent and received by your computer How I’m not a l33t h4x0r Ok, let’s go! Leave a comment: Do tell me what you liked and understood Do tell me what […]